In a first, researchers have developed a vaccine for the three main pathogens that cause traveller's diarrhoea and deaths of children in developing countries, where it is estimated that these three common pathogens kill more than one lakh children under age five each year.


 

Traveller's diarrhoea is a digestive tract disorder that commonly causes loose stools and abdominal cramps. According to the US Centres for Disease Control and Prevention (CDC) estimates, up to 80 per cent cases of travellers' diarrhoea are caused by bacteria. The novel conjugate vaccine yokes together proteins from pathogenic Escherichia coli or E. coli with sugars from Shigella and Campylobacter jejuni. All three bugs are major causes of bacterial diarrhoea globally.

In tests on mice, the vaccine provided immunity against all three pathogens, said Professor Mario Monteiro, a chemist at the University of Guelph in Canada. Currently, no licensed vaccines exist against any of these pathogens. Monteiro had, in 2009, developed a sugar-based vaccine that worked only against campylobacter. It is undergoing human trials but is still an estimated decade away from potential release.

Monteiro noted that the new three-in-one approach, published in the journal Vaccine, may ultimately overtake the earlier single-target vaccine, although any new vaccine may take decades to test and release. "We're targeting three pathogens at the same time," he said. "Instead of three shots, maybe you only need one." Monteiro said further research is needed to determine the optimum amounts of protein and sugars in the vaccine and to make the vaccine more efficient.